1. Technical Field
The present device relates generally to horticultural lighting fixture used for growing plants in controlled environments.
2. Discussion of Related Art
Indoor gardens, green houses, hydroponics systems, and isolated carbon dioxide growing chambers demand careful regulation of temperature, light, hydration, nutrients, and humidity. In these controlled environments, one of the major challenges is providing adequate light intensity, while efficiently and effectively removing the heat generated by the light source. A second major challenge relates to the manufacturing of the horticulture fixture in an economical way, utilizing inexpensive materials and manufacturing processes. Horticulture lighting systems depend on grow lamps as a primary light source. Commonly used grow lamps are high pressure sodium and metal halide. These grow lamps get exceptionally hot when confined in a horticulture lighting fixture. The heat generated may curl new growth on plants, dry out the soil or planting medium, and if the heat is not dissipated, the grow lamp will have a reduced life span. These undesirable effects reduce yields and increase operational costs.
Several air cooled horticulture light fixture designs incorporate sheet metal enclosures in combination with a transparent shield or glass between the grow lamp and the developing plants, sealing the heat generated from the lamp while allowing the desired light to pass. Some fixtures even benefit from forced air cooling wherein a fan blows cooling atmosphere through the fixture exhausting the heated air out of the growing environment, and away from plants.
This problem of energy being absorbed and then radiated was addressed by U.S. Pat. No. 6,595,662 issued in July 2003 to Wardenburg disclosing an air cooled double walled fixture wherein cooling air was introduced via conduit on one end and exhausted out the other side, and a transparent portion was located between the grow lamp and the plants allowing for light to pass while isolating the lamp and it's heat from the growing environment. Wardenburg did not disclose or teach the fixture having glass retention rails for removably engaging and sealing glass to the bottom of the fixture allowing for easy cleaning and maintenance.
U.S. Pat. No. 6,267,483 issued in July 2001 to Hembery discloses a straight and continuous channel of air flow through a transparent tube. The Hembery device isolates the grow lamp from the growing plants by centering the grow lamp within the transparent tube. Free flowing air enters one end of the fixture and free flows out the other side. The Hembery device absolutely depends on a transparent tube, and the transparent material of choice is borosilicate glass that is heavy and expensive. Hembery fails to teach construction from low cost material or manufacturing method such as sheet metal and the efficient process of forming and shaping sheet metal.
U.S. Pat. No. 6,247,830 issued in June 2001 to Winnett et al. discloses a forced air transparent tube fixture that senses the temperature of the fixture and shuts the grow lamp down if the temperature exceeds a predetermined maximum safe operating level. The Winnett device also relies on a transparent tube that must withstand high temperatures which is expensive and fails to teach the use of inexpensive sheet metal and sheet metal processes.
Not one of the above discussed inventions, taken either singularly or in combination, teach the instant invention as claimed. What is desired is a horticulture light fixture primarily constructed from inexpensive sheet metal formed by efficient sheet metal processes, having a glass retention structure that provides easy glass removal for cleaning and fixture maintenance, while said glass retention structure provides positive compressive force sealing the glass to the fixture via gasket, thus isolating the growing plants from the generation of grow lamp heat.